Calibration Periods

All EOI equipment is calibrated at EOI prior to shipment. Calibration is traceable to . Recommended calibration cycle is either six months or one year depending on the precision of the equipment. This certification period is based on experience with equipment in a typical laboratory environment. Many customers ask us if the calibration period can be extended. Unfortunately there is not a simple yes or no answer.

There are no specific military or commercial guidelines which identify a firm schedule for calibration of temperature sensors. The existing standards require only that a calibration cycle be established and adhered to in order to fulfill the requirements.

Usage can greatly affect the need to re-calibrate. Equipment used in a laboratory with low accuracy requirements may only need to be calibrated every two years. Equipment used in the field or with demanding accuracy requirements may need calibration every few months. When a critical test is scheduled, it may be advisable to perform both a pre and post test calibration.

Temperature sensors and the read out electronics are complex assemblies of wires, connectors, dissimilar metallurgies, electronic packages, etc. The stability of this compendium of components are dependent on the operating environment, and history of usage. Some of the environmental effects include;

	Thermal Shock
	Mechanical Shock
	Electrical Stress
	Electrostatic Discharge
	Corrosion of Dissimilar Metals (such as the sensor probes and electronics packages)
	Deterioration or Contamination of the Emitting Surface         (EOI recoats the emitting surfaces as part of calibration)

Every customers usage history will be different. EOI suggests that customers start with the recommended equipment calibration cycle if the equipment is used in a typical laboratory environment. A shorter cycle may be required in more demanding test environments or if there is evidence the reading have shifted.

Keeping a history of performance over time, comparing the before and after calibration values, and understanding the testing accuracy requirements will allow the calibration cycle to be adjusted to maintain the level of accuracy required for your testing.

Many customers maintain internal metrology laboratories or rely on commercial metrology laboratories for calibration services. However, most facilities do not have the knowledge or facilities to re-coat the emitting surfaces of a blackbody. The emitting surface coating has a direct influence on the total emissivity of a blackbody. If your calibration facility does not perform this vital task, EOI recommends the equipment be returned to EOI for calibration & re-coating.